The present invention is directed to the decorative container art and, more particularly, to a composite container comprised of a blow molded body and an integral support, a related method of forming such a container, and a mold for use in forming the container using a blow molding process.
The use of plastic containers continues to grow in the consumer market at a rapid rate and promises to continue in years to come. In many marketing areas, such as for liquid or semi-liquid (viscous) cosmetics and related products, the plastic container, such as a bottle or jar, is by far the container of choice. A plastic container is not only non-breakable, but can be molded into different shapes so as to be very attractive, as well as functional. In addition, from a cost standpoint, the use of plastic is very competitive with the other materials often used to form containers, such as glass.
One of the most popular containers used for cosmetics, as well as other liquid and semi-liquid products, is the blow molded bottle or jar. Usually, the containers are fabricated of a clear, translucent or opaque plastic material. For example, polyethylene terephthalate (PET) with additives for varying light transmission and/or color is used to form most types of cosmetic containers. Of course, other materials can also be chosen depending on various factors, such as the type of product container, the desired size or shape of the container, the expected or required service life, any recycling/environmental considerations, or inherent cost constraints.
In addition to merely containing product, the container should be aesthetically pleasing, since the appearance may influence the customer""s purchasing decision. As noted above, the attractiveness of the container may be enhanced by forming it having a distinctive or irregular shape, as well as by using eye-catching colors and possibly with intricate surface patterns or designs. Many different types of containers embodying some or all of these features have been proposed in the past. However, in the case of the popular blow molded containers, the range of shapes available are somewhat limited by the nature of the blow molding process. For example, using a conventional tubular preform or parison alone, it is generally difficult, if not impossible, to blow a unitary, self-supporting container that simulates the appearance of the wide base and slender stem portions typically found on a conventional wine glass. Hence, a need is identified in the art for a novel container having this desirable appearance formed using inexpensive and highly efficient blow molding techniques.
The present invention comprises: (1) a composite container formed using a blow molding process having an integral support or stand that is aesthetically pleasing and provides with an added dimension of functionality not found in prior art containers with integral base members that merely structurally enhance the corresponding container; (2) a related method for forming a container with an integral support or stand; and (3) a mold for use in forming such a container.
In accordance with a first aspect of the invention, a composite container formed using a blow molding process is disclosed. The container comprises a hollow body formed by the blow molding process and a support having a first end with a plurality of slits. At least one of the slits at least partially receives a first portion of the body during the blow molding process. A second end of the support engages a support structure, such as a non-integral base or a stable surface.
In one embodiment, the first end of the support includes a generally planar surface in which at least a portion of each of the plurality of slits is formed. Preferably, this first end of the support is generally frusto-conical and includes a peripheral sidewall having a ledge that engages a second portion of the blow molded body. This second portion blouses over the peripheral sidewall and ledge as a result of the blow molding process, which creates a substantially uninterrupted transition from the support to the body of the resulting container. Each of the plurality of slits may extend radially from a common center in the first end of the support. The first end of the support may also include a peripheral sidewall adjacent to the ledge, with the slits extending from adjacent a center of the first end of the support through the peripheral sidewall.
The first end of the support may also include a bore located substantially in the center of the radially extending slits. Hence, during the blow molding process, the bore also receives at least a portion of the body. In one embodiment, the bore has an opening that is smaller in cross section than a base portion of the bore. Accordingly, the sidewall of the bore is tapered to form an undercut that captures the portion of the blow molded body received therein.
The support may include a leg having a plug. In that case, the support structure is a base having a socket for receiving the plug such that the resulting assembly is capable of self-support. Alternatively, as noted above, the base may be integrally formed with the leg, in which case neither the plug/socket arrangement nor the separate attachment step is required.
In accordance with a second aspect of the invention, a self-supporting composite container formed using a blow molding process is disclosed. The container comprises a hollow body formed during the blow molding process and a support. The support includes a first end for engaging a portion of the blow molded body and a second end having a leg. At least one base is provided for mating with the leg to support the body above a stable structure.
In one embodiment, the first end of the support includes a plurality of openings. During the blow molding process, a plurality of portions of the body penetrate into these openings. The openings may be in the form of grooves, slots, notches, furrows, channels, combinations thereof, or any other type of narrow, elongated openings, but are preferably radially extending slits. The slits communicate at a first end thereof with a central bore and at the opposite end thereof with a peripheral sidewall formed in the first end of the support. Preferably, the first end of the support is frusto-conical and includes an planar surface and a peripheral ledge for engaging a portion of the blow molded body blousing over the planar surface during the blow molding process. Also, the base may be integrally formed with the leg.
In accordance with a third aspect of the invention, a method for producing a self-supporting composite container using a blow molding process is disclosed. The method comprises positioning a support having a first end including a plurality of slits in or adjacent to a mold cavity and blow molding a parison or preform in the mold cavity and over the support such that at least a portion thereof is received in one or more of the plurality of slits. The engagement between at least a portion of the parison or preform and the one or more slits in the support creates a secure connection.
In one embodiment, the support further includes a second end having at least one leg, and the method further comprises attaching a base to the leg such that the base supports the composite container on a stable support structure. The mold cavity may further comprise a plurality of mold portions for closing over the preform. At least one of the portions includes a receiver for receiving the leg of the integral support during the blow molding process and holding the support adjacent to the mold cavity. The method may further include placing the leg of the support in the opening prior to blow molding the parison or preform in the mold cavity. Also, the step of blow molding may involve stretch blow molding a preform in the mold cavity using a stretch rod, whereby a bottom portion of the preform is forced into engagement with the first end of the support by the stretch rod.
In accordance with a fourth aspect of the invention, a mold for forming a composite article from a blow molded parison or preform with an integral support having a first end for engaging the parison or preform and a second end including a leg is disclosed. The mold comprises a plurality of mold portions for closing over the preform to create a mold cavity. One of the portions includes a receiver for receiving the leg on the second end of the support during the blow molding process and holding the first end in or adjacent to the mold cavity. Hence, upon blow molding, the parison or preform expands in and fills the mold cavity as the result of biaxial stretching such that at least a portion thereof attaches to the first end of the support. In one possible embodiment, the support includes an integral base connected to the leg, and the receiver is adapted for receiving both the leg and the integral base. In this case, the blow-molded article is capable of self-support in a stable fashion immediately upon being removed from the mold.